I've been battling a badly corroded/dexcool sludged coolant system. Last night I replaced my accessory tensioner and thought I would flush my coolant system while I was at it. I removed the thermostat that was stuck open anyway and began the flush. I backflushed the system until the water ran clear. I then ran Cascade powder/water through it for a few hours and let it sit while I went to the bar. Took it home and drained the radiator and again backflushed until it ran clear. I then put a bottle of Peak Performance radiator cleaner in it with the intention on letting it run while I napped for the necessary 3-6 hours. I filled the radiator with water and began trying to burp the air out of the system.
I kept filling until I no longer got bubbles at the radiator and then opened the bleeder valve on the thermostat housing. I got plenty of air coming out, but never could get any liquid to come out. I tried for nearly an hour, squeezing the top radiator hose, etc, but to no avail. With the car running a little hot at around 200 degrees and the fact that there was still air in the system, I didn't feel comfortable letting it run unattended.
What am I missing here? I figured without the T-stat it would run really cold like it did while I had the Cascade flush in it.
I have to get this taken care of tomorrow morning before heading to work, as it's supposed to drop below 30 degrees so I need to get coolant back in it.
Your thoughts?
Also, do I need to replace the thermostat every time I do a flush? I think its going to take a huge number of flushes before I get this system near clean and am going to go through a small fortune in coolant and thermostats